Reference is made initially to DE 28 06 405 A1 as the prior art. According to this publication, an artificial sphincter is frequently implanted in cases of urinary incontinence or as a result of injury of removal of the external urethral sphincter following adenectomy of the prostate, radical prostatectomy, neurogenic urinary incontinence, and hyperactivity of the urethral sphincter and congenital urethral muscle defects. In a pneumatic sphincter referred to therein, an inflatable cuff surrounds the urethra so that the cuff can be inflated, preventing the escape of urine through the urethra. The urethra is released by venting the air from the cuff so that the urinary bladder can be emptied. This device must be implanted. A device for pumping air into the inflatable cuff is impractical and burdensome and may often be unsuitable for the user.
In a mechanical sphincter device also referred to, a coil, ring, or torus surrounds the urethra and is deliberately contractible by a control device by the user, preventing the escape of urine. To control the degree of contraction and to avoid adjustment that requires additional surgery involving bleeding, DE 28 06 405 A1, as an improvement on the device described above, provides a device for preventing the closing force from increasing beyond a predetermined closed position to protect the passageway against excessive or harmful closure.
British Patent 1,174,814 teaches an artificial sphincter with a closing body operated pneumatically, hydraulically, mechanically, or electrically, said body being connected directly or indirectly with an actuating device in order to permit actuation of the body to close or open the passageway.
DE 35 21 602 A1 teaches an endourethral sphincter prothesis which is implantable in the prostate cavity that has been cleared. This prosthesis has a short tubular section surrounded by a housing, said section extending from the neck of the bladder to the urethra. To adapt the sphincter prosthesis to the lumen of the empty prostate capsule, a balloon-like bladder made of thin, rubbery material is located around the prosthesis housing, into which bladder rapidly curing silicone foam is injected so that the bladder adjusts to the inside wall of the prostate capsule.
The tube section inside the housing is surrounded by a pressure cuff or a pinch valve. An actuating device is provided for its actuation, said device comprising a hydraulic chamber located in the lower body of the patient, from which chamber a connecting tube extends to a control pump located in the scrotum, from which a tube in turn leads to the cuff or the pinch valve.
It is also disadvantageous in this regard, even if the prosthesis is located in the wound space left by the prostate so that the valve mechanism does not act on the urethra but upon an artificial tubular section, that the entire device must be implanted, i.e. inserted with bleeding. Moreover, it is complex and cumbersome.
The above publication itself also refers to sphincter prostheses according to Rosen with a hydraulically operated clamp acting on the urethra and a prosthesis according to Kaufmann, Kelami-Affeld, and Scott in which a hydraulic cuff in the filled state exerts compression on the urethra, with the actuating elements for controlling the sphincter prosthesis being located out of the way and free of irritation in the scrotum. The subject of DE 35 21 602 A1 includes an improvement on the latter design in order to avoid precisely the disadvantages caused by the action of the valve or clamp on the urethra itself.
EP 348 114 B1 teaches a likewise implantable, i.e. therefore insertable in an operation involving bleeding, artificial closing muscle for a human passageway in the body, more specifically the male urethra. This has a cuff located around the urethra and, when inflated, closes down around the passageway in the body and blocks it, and when it is emptied, allows the body passage to open. The cuff is connected by lines with a pump implantable in the scrotum. A publication --Grein, U., Schreiter, F., 15 Years of Artificial Sphincters --The Schwelmer Results, Z Poster Report --Urology 1/1989, reports on the use of such an artificial sphincter with a sphincter cuff, pressure-regulating chamber, and a pump with control unit, in which activation is accomplished by pressure on the pump implanted in a prepared scrotal pouch or in the labiae majorae. Other previous models are mentioned, the first of which consisted of a reservoir, two pumps, a sphincter cuff, and four valves in tubes between these parts. In another, a pressure-regulating chamber resulted in the elimination of valves. In addition, a reservoir was provided for retarding the fluid flow of the hydraulic system.
These artificial sphincters are implanted by surgery, involving an abdominal incision with incision of the fascia endopelvina adjacent to the prostate and formation of a shallow cavity below the prostate, and after determining the length of the cuff, pulling the latter over the urethra and intraperitoneal installation of the pressure-regulating chamber, placement of the pump in the scrotal pouch or labiae majorae, and finally completion of the tube connections.
In addition, a magnetic urethral closure has been proposed (Z. Urologie 6 (1990)).
The goal of the invention is to provide an artificial sphincter which does not have to be implanted, in other words does not have to be installed by surgery involving bleeding, and in which no additional control devices implanted at other locations in the human body or tubular connections are required. The goal of the invention is also the provision of sets for voluntary closure of the urethra by means of such a sphincter as well as a method for installation of the sphincter.
According to the invention, this goal is initially achieved by an artificial endosphincter for the urethra, which comprises a valve body to be installed in the urethra, with a valve manually operable from the outside by exerting pressure.
The artificial endosphincter according to the invention is inserted through the urethral opening into the latter up to a position, preferably in the vicinity of the natural sphincter to be replaced, i.e. in the vicinity of the pelvic floor, and anchored there by the anchoring part. The self-closing valve located in the valve body is opened by direct actuation from the outside, by exerting radial pressure on the penis from the outside in the vicinity of the valve; for this purpose, the patient for example presses on the penis from above and below. He can thus open the valve and permit the flow of urine. When external pressure is exerted, the valve remains closed so that the urine is retained in the urinary bladder.
In an embodiment with an anchoring part for securing the valve body in the urethra, in a preferred embodiment provision is made such that the anchoring part and valve body are releasably connected with one another. In this embodiment, the anchoring part and valve body can be inserted separately in succession into the urethra so that an epithelium can form initially, after the anchoring part is inserted, over the latter before the valve body is installed in the anchoring part. This embodiment also has the advantage that the valve body, for example if the valve becomes encrusted, can be removed but the necessarily epithelialized anchoring part can remain in the urethra and a new valve body can be inserted and secured in the anchoring part. Alternatively, however, provision can also be made for the anchoring part and valve body to be permanently connected together in such fashion that they cannot be separated without damage.
A highly preferred embodiment provides that the anchoring part comprises a cylindrical main body with a first diameter and at one end a likewise cylindrical end section with a smaller, second diameter, and that the main body and the end section are permanently connected by means of an expanding retaining area for the valve body, with the retaining area being made shoulderwise and especially the retaining area having an expanding area that expands trumpetwise from the end section and a tapering section that is drawn in in the form of an arc from the main body to the expansion section. Provision can also be made in an improvement such that in addition an intermediate section that expands partially conically can be provided between the expanding section and the tapering section.
As a result, a positive connection is produced between the anchoring part and the valve body which, for separation of the latter from the former, with an elastic or flexible design, at least of the tapering and constricted area of the anchoring part and/or the expanding area of the valve body, can be released by applying a greater tensile force. The desired radial flexibility of the anchoring part can be achieved in the preferred embodiment by virtue of the fact that the anchoring part has openings in its jacket wall, with the anchoring part in particular having rhombic openings in its configuration for use. In an alternative embodiment, however, provision can also be made such that the anchoring part is in the form of a coil spring.
Preferably the anchoring part consists of a shape memory alloy such as a nickel-titanium alloy known in one preferred embodiment by the name Nitinol. With such an embodiment, the anchoring part can be inserted, in its low-temperature configuration that has very limited transverse dimensions, into the urethra by means of suitable insertion elements, and expands at human body temperature, which is significantly above the transition temperature of this material, into its high-temperature configuration with larger radial dimensions in which the anchoring part abuts the walls of the urethra and ensures a secure grip there.
An improvement on the endosphincter according to the invention provides that the valve body has a tubular cylindrical main body extending from the retaining area with a smaller diameter than the retaining area. To ensure that no urine can run along the inside wall of the urethra at the edge of the endosphincter and to ensure a sufficiently secure closure, another preferred embodiment provides that the cylindrical main body is provided with sealing lips near the retaining area, whereby in particular the sealing lips extend radially slightly beyond the retaining area.
The invention also includes an anchoring part for securing a functional element such as a valve body in a body passage with the features described above for the anchoring part of the endosphincter according to the invention.
The invention also includes a set for releasable closure of the urethra characterized by an anchoring part and by a valve body connectable with the anchoring part with a valve that is manually operable from the outside by exerting pressure with the valve body being securable in the urethra by the anchoring part. In addition, the device according to the invention includes the provision of a set for releasable closure of the urethra, characterized by a valve body anchorable in the urethra and a device for inserting the valve body into the urethra with a stop as a retainer for the valve body and with an external cannula tube for releasing the valve body, said cannula tube surrounding the stop, receiving the valve body, and being retractable up to the stop.
Another embodiment of a set according to the invention for releasable closure of the urethra is characterized by an anchoring part connected with the valve body and insertable together with the latter in the urethra, whereby in particular a device is provided for initially inserting an anchoring part into the urethra with a retainer for the anchoring part and an external cannula tube for releasing the anchoring part in the urethra, said cannula part surrounding the retainer and receiving the anchoring part, as well as being retractable relative to the retainer. In such an embodiment, additional provision is made such that the diameter of the anterior end of the cannula tube is smaller than the diameter of the end section of the anchoring part or that a guide tube surrounding the valve body and extendable from the outer cannula tube is provided inside the outer cannula tube, said guide tube being divided at its free end into flexible fingers whose free ends are bent toward one another.
A first method for insertion of an endosphincter according to the invention with an anchoring part and valve body permanently connected together provides that insertion elements receiving the endosphincter consisting of a valve body and an anchoring part permanently connected therewith, for insertion of the endosphincter into the urethra, is introduced through the urethral opening into the urethra up to the vicinity of the pelvic floor, and then an outer cannula tube containing the endosphincter is retracted as part of the insertion elements in the direction of the urethral opening relative to a retainer (stop) for the endosphincter, whereupon an anchoring part initially emerges from the outer cannula tube and, because of its intrinsic elasticity, expands radially at human body temperature and becomes anchored in the vicinity of the pars membranacea of the urethra and, with further retraction of the cannula tube, the entire endosphincter is released.
A two-stage method for insertion of an artificial endosphincter into the urethra is characterized in that an inserting element, containing an anchoring part, of a device for insertion of the endosphincter into the urethra is introduced through the urethral opening into the latter up to the vicinity of the pelvic floor, and an external cannula tube containing the anchoring part, with retention of the anchoring part, is released by a retainer in the vicinity of the pelvic floor, so that the anchoring part becomes anchored in the vicinity of the pars membranacea of the urethra as a result of elastic radial expansion at body temperature, and in that, after removal of the insertion elements for the anchoring part, an insertion element containing a valve body is inserted through the urethral opening into the urethra up to an external tapered end section of the anchoring part, and in that a retaining section of the valve body is inserted through the tapered end section of the anchoring part into a retaining area thereof. In an improvement, provision is made such that for insertion of the retaining area of the valve body into the retaining area of the anchoring part, an anterior end area of an outer cannula tube of the insertion element, receiving the valve body, is inserted into the tapered area of the anchoring part and then the valve body together with its retaining area is inserted into the anchoring part or that, to mount the retaining area of the valve body in the retaining area of the anchoring part after insertion of the cannula tube containing the valve body up to the tapered end section of the anchoring part, in its free end area the elastic fingers, bent toward one another, of a guide tube mounted to surround the valve body and located inside the cannula tube are brought out of the cannula tube and inserted into the tapered end area of the anchoring part with the valve body until the retaining area of the valve body reaches the retaining area of the anchoring part and that the cannula tube and the guide tube are then retracted relative to the retainer, whereby initially the retaining area of the valve body inside the retaining area of the anchoring part is released and then the entire valve body is released into the urethra. Insertion of the insertion elements and removal of the anchoring part and/or the valve body are preferably performed under inspection with an endoscope.
Further advantages and features of the invention will follow from the claims and the following specification in which preferred embodiments of the invention are discussed in detail with reference to the drawings.